Use and Substitutes
Whey isolate is industrially filtered and can't be made sensibly at home. For recipes, it depends on the purpose.
For creamy dips or fillings
Replace 30 g whey isolate with 120 g skyr or low-fat quark and reduce the remaining liquid by about 90 ml.
For pancakes and soft doughs
Replace 30 g whey with 20 g skim milk powder plus 10 g flour. If you have neither, use 30 g flour and add an egg or 100 g skyr for more protein per serving.
For pizza or bread dough
Never replace large amounts of flour with whey; more than 5-8% of the flour weight dries the dough out. When leaving it out, use the same gram amount of flour and increase the water by about half that amount to start.
Simple protein dip
Mix 250 g skyr, 1 tsp mustard, 1 tsp lemon juice, herbs, salt and pepper. Without any powder, this makes about 2 hearty portions.